Flora: Add `real_physics` option

game_api.md

@@ -373,6 +373,7 @@ The flora API is meant to allow registration of plants and their characteristics
 #### Plant definition
 ```lua
 flora.register("cactus", {
+	real_physics = true, -- Controls whether the node requires an adjacent solid node
 	node = {
 		description = "Cactus",
 		tiles = {"flora_cactus.png"},

mods/flora/init.lua

@@ -6,10 +6,63 @@ flora = {}
 --- API
 ---
 
+-- [local function] Get connected nodes
+local function get_connected_nodes(pos, nodenames, iterator)
+	local ret = {}
+	local nodes = {
+		{x=pos.x + 1, y=pos.y,     z=pos.z},
+		{x=pos.x - 1, y=pos.y,     z=pos.z},
+		{x=pos.x,     y=pos.y + 1, z=pos.z},
+		{x=pos.x,     y=pos.y - 1, z=pos.z},
+		{x=pos.x,     y=pos.y,     z=pos.z + 1},
+		{x=pos.x,     y=pos.y,     z=pos.z - 1},
+	}
+
+	for _, p in pairs(nodes) do
+		local node = minetest.get_node_or_nil(p)
+
+		if node then
+			for _, n in pairs(nodenames) do
+				if n == node.name then
+					ret[#ret + 1] = p
+
+					if iterator and type(iterator) == "function" then
+						iterator(p)
+					end
+				end
+			end
+		end
+	end
+
+	return ret
+end
+
 -- [function] Register flora
 function flora.register(name, def)
 	def.node.is_ground_content = false
 
+	if def.real_physics then
+		local after_dig = def.node.after_dig_node
+		def.node.after_dig_node = function(pos, node, meta, digger)
+			if after_dig then
+				after_dig(pos, node, meta, digger)
+			end
+
+			if digger then
+				get_connected_nodes(pos, {"flora:"..name}, function(pos)
+					local node = minetest.get_node_or_nil(pos)
+					local node_under = minetest.get_node_or_nil({
+						x = pos.x, y = pos.y - 1, z = pos.z
+					})
+
+					if node and node_under and node_under.name == "air" then
+						minetest.node_dig(pos, node, digger)
+					end
+				end)
+			end
+		end
+	end
+
 	minetest.register_node("flora:"..name, def.node)
 	minetest.register_decoration(def.decoration)
 end
@@ -19,6 +72,7 @@ end
 ---
 
 flora.register("cactus", {
+	real_physics = true,
 	node = {
 		description = "Cactus",
 		tiles = {{name = "flora_cactus.png", backface_culling = true}},